Abstract No. 584 Comparison of clinical outcomes in pedal and intranodal lymphangiography prior to thoracic duct embolization in traumatic chylothorax

Intranodal lymphangiography has largely replaced pedal lymphangiography as a method to opacify the thoracic duct prior to catheterization of the cisterna chyli. This study compares technical and clinical success rates, and procedure duration between lymphangiography techniques. Records of 221 thoracic duct embolizations (TDEs) in 201 patients with traumatic chylothorax between 2002-2018 were reviewed. In 96 patients pedal lymphangiography (PL) and 125 intranodal lymphangiography (IL) were used as an imaging tool. In addition to technical and clinical success, procedure time, fluoroscopy time and complications were collected. Clinical success was defined as resolution of chylothorax and removal of chest tubes within 7 days of TDE. Patients receiving TDE with IL had significantly higher clinical success rates compared to PL (89.9% vs. 78.9%, P = 0.045) though clinical success on a per-procedure basis was similar (79.7% for IL, 74.0% for PL, P = 0.33). A repeat TDE attempt was made in 56.0% of IL patients whose initial TDE was unsuccessful compared to 24.0% in the PL group (P = 0.04). Thoracic duct cannulation was achieved in 85.4% of IL procedures and 79.2% of PL procedures (P = 0.28). The complication rate was similar in both groups (5.6% in IL, 9.4% in PL, P = 0.31). Successful TDEs with IL had a significantly shorter mean procedure time of 112 minutes compared to PL (192 mins, P <0.0001). Within IL cases, mean procedure time of successful TDEs was significantly shorter from 2016-2018 than from 2011-2015 (90 mins vs. 124 mins, P < .0001). Average fluoroscopy time from 2016-2018 was 34 minutes compared to 42 minutes from 2011-2015 (P = 0.06). Though per-procedure clinical success rates are not significantly different, clinical success on a per-patient basis is significantly higher with IL. This may be due to greater technical feasibility of repeat IL after failed TDE, as compared to repeat PL. IL also significantly shortens mean procedure time, and trends within the IL group over time suggest increased operator experience is associated with further reductions in procedure and fluoroscopy time. These findings support the adoption of IL prior to TDE.